114 GENERAL PRINCIPLES. 



aid than nature, because the tree assumes the form most 

 in harmony with the natural tendency of the sap.* 



" But in those submitted to pruning, it is different ; the 

 forms imposed on them, such as espalier, pyramid, vase, 

 etc., change more or less the normal direction of the sap, 

 and prevent it from taking the form proper to its species. 

 Thus nearly all the forms given to trees require the devel- 

 opment of ramifications more or less numerous, and of 

 greater or less dimensions at the base of the stem. And, 

 as the sap tends by preference towards the summit of the 

 tree, it happens that, unless great care be taken, the 

 branches at the base become feeble, and finally dry up, 

 and the form intended to be obtained disappears, to be 

 replaced by the natural form, that is, a stem or a trunk 

 with a branching head. It is then indispensable, if we 

 wish to preserve the form we impose upon trees, to em- 

 ploy certain means, by the aid of which the natural direc- 

 tion of the sap can be changed and directed towards the 

 points where we wish to obtain the most vigorous growth. 

 To do this we must arrest vegetation in the parts to which 

 the sap is carried in too great abundance, and on the con- 

 trary favor the parts that do not receive enough. To ac- 

 complish this the following means must be successively 

 employed. 



" (1.) Prune the branches of the most vigorous parts very 

 short, and those of the weak parts long. We know that the 

 sap is attracted by the leaves. The removal of a large 

 number of wood-buds from the vigorous parts, deprives 

 these parts of the leaves which these buds would have pro- 

 duced ; consequently the sap is attracted there in less 

 quantities, and the growth thereby diminished. The feeble 



* This is not true in all cases. Peach trees, we know, in our climate, left to 

 themselves, exhibit a very striking example of the unequal distribution of the 

 sap. The ends of the branches attract nearly the whole, leaving the lateral shoots 

 and lower parts to die out. In other species, similar instances might be quoted, 

 and as a general thing, the proposition is unsound, except in a comparative 

 sense. 



